鲁西地区山西—太原组泥页岩可压性分析

山西—太原组泥页岩是鲁西地区良好的页岩气储层,为了获取山西—太原组泥页岩可压性,在岩性编录、样品分析测试、泥页岩扫描电镜、X衍射—全岩/黏土等资料基础上,对山西—太原组岩性特征、有机地化特征、微裂隙发育情况、脆性矿物含量、脆性指数进行了研究。结果表明:鲁西地区山西—太原组泥页岩发育厚度为80~120 m,泥地比大于60%;泥页岩有机碳含量平均为3.1%,干酪根以Ⅲ型为主,镜质体反射率一般为0.8%~1.4%;泥页岩中微裂隙发育,部分微裂隙沿矿物间隙延伸,利于形成网状体积裂缝;泥页岩脆性矿物含量较高,平均为38%~63%;山西—太原组泥页岩脆性很强,山西组泥页岩样品脆性指数主要集中在50%~70%,太原组泥页岩样品脆性指数主要集中在40%~60%,充分说明山西—太原组泥页岩具有较好的可压性,利于人工压裂改造。研究成果对鲁西地区山西—太原组页岩气储层改造具有很好的借鉴意义。

Compressibility Analysis of Shale in Shanxi-Taiyuan Formation,Luxi Area

The shale of Shanxi-Taiyuan formation is a good shale gas reservoir in Luxi area.In order to obtain the compressibility of the shale in Shanxi-Taiyuan formation,based on lithology cataloging,sample analysis and testing,scanning electron microscope,X-diffraction-total rock/clay,we have studied the lithology,organic characteristics geochemical characteristics,microfracture development,brittle mineral content,and brittleness index of Shanxi-Taiyuan formation.The results showed that the development thickness of the shale of Shanxi-Taiyuan formation in Luxi area is 80~120 m,and the mud-land ratio is more than 60%.The organic carbon content of the shale is 3.1%on average,the kerogen is mainly typeⅢ,and the vitrinite reflectance is generally 0.8%to 1.4%.The micro-fractures in the shale are developed,and some micro-cracks extend along the mineral gap,which is favorable for the formation of reticular volume cracks.The content of brittle minerals is high,and the average content of brittle minerals is between 38%and 63%.The shale of Shanxi-Taiyuan formation is very brittle.The brittleness index of the shale samples in Shanxi is mainly between 50%and 70%.The brittleness index of the group shale samples in Taiyuan is mainly concentrated between 40%and 60%.The above is fully explained that Shanxi-Taiyuan formation shale has good compressibility,which is conducive to artificial fracturing and transformation.And the research results have a good reference for shale gas reservoir reconstruction in Shanxi-Taiyuan formation,Luxi area.